Answer:
6.1° ; 425.86 m.
Step-by-step explanation:
So, we are given from the question that; ''airplane 5.7 miles above the ground." and the "Earth's radius is approximately 4000 miles." Hence,
θ = 2 × cos^-1 (a/ a + b). Where a= 4000 miles and b = 5.7 miles.
θ = 2 × cos^-1 (4000/ 4000 + 5.7) = 6.1°.
The distance in metres can be calculated as;
Change in distance = 6.1° /360° × 2π × 4000 miles. = 425.86 metres.
Hence, the measure of BD⌢ =6.1° and the distance of the portion of the earth can be sent as 425.86 metres.